Some optical modules having an optical transceiver function includes pluggable modules that is removably inserted. Outer dimensions or the forms of electrical connections of such pluggable modules are standardized, and different specifications such as transmission and reception functions, transmission rates, or optical wavelengths of module components are offered as selectable specifications.
For example, when Small Form-factor Pluggable (SFP) modules performing 2.5 Gbps optical communication, 10 Gbps Small Form-factor Pluggable (XFP) modules performing 10 Gbps optical communication, or the like are used, specifications or transmission capacity of an optical transmission device may be easily changed by adding or removing module components to be housed.
Related art is disclosed in Japanese Laid-open Patent Publication No. 2009-152427 and the like.